JPH0442600A - Method for recognizing position of flat package type electronic parts - Google Patents

Abstract

PURPOSE:To reduce the mounting time of flat package type electronic parts by irradiating the whole body of the parts including lead wires with light at picturizing brightness and accurately aligning the parts through pictorial recognition after roughly aligning the part through pictorial recognition while only the package section excluding the lead wires is irradiated with light at picturizing brightness. CONSTITUTION:A flat package (FP) IC 1 held by a mounting head 2 by adsorption is brought to the position immediately above an image pickup means 5 by moving an X-Y table 3 and the image of the package section of the IC 1 only excluding lead wires is taken while the part is irradiated with light from a lighting device 4 set at picturizing brightness. This image pickup can be realized by increasing the luminous intensity of the device 4. Rough alignment is performed by pictorially recognizing the square shape of the package section and calculating the dimension, center of gravity, and inclination of the package section by means of a controller 6. Then rotational dislocation is corrected by rotating the mounting head 2. thereafter, the image of the entire body of the parts including the lead wires is taken by irradiating them with light from the lighting device 4 set at brightness at which they can be picturized. This time, the luminous intensity of the lighting device is decreased.

Description

[Detailed Description of the Invention] 5. Field of Industrial Application The present invention is directed to the positioning of flat package (hereinafter abbreviated as FP) type electronic components, such as packaged IC elements, when mounting and mounting them on a printed circuit board. The present invention relates to a position recognition method suitable for use in applications such as the following.

(b) Conventional technology: As a method for accurately mounting FP type electronic components such as packaged IC elements at predetermined positions on a printed circuit board, ``imposition is an automatic component mounting method'' described in Japanese Patent Application Laid-Open No. 62-86789.
and ``Method for positioning flat package type element'' in Japanese Patent Application Laid-Open No. 64-50500.

That is, in the former case, as shown in FIG. 3, two sample straight lines 8 are set so as to be substantially orthogonal to the image pattern of the lead Kariyas of the FP type component. Then, the position of the lead Kariya is determined from the change in brightness on the sample straight line 8, and based on that position, the positional deviation and rotational deviation of the entire FP type part are calculated. Furthermore, the position of the component mounting head is corrected based on this shift information to accurately mount the component.

As shown in FIG. 4, the latter recognizes the two diagonal corners of the package based on the image pattern of the FP type component, and first performs approximate positioning. Next, highly accurate positioning is performed for the two located corners based on the leads near each corner.

(9) Problems to be Solved by the Invention In the former "imposition is an automatic component mounting method", if the FP type component has rotational deviation or suction position deviation while being held by suction, the sample straight line is almost perpendicular to the lead row. In some cases, the lead image could not be set within the field of view of the TV camera, resulting in longer image recognition times or even inability to perform recognition itself. Although the FP type component can be positioned with high accuracy regardless of rotational deviation or suction position deviation in the FP type component, the positioning method takes a relatively long time and is not suitable for the purpose of increasing speed.

B) Means for Solving the Problems Considering these points, the method for recognizing the position of an FP type electronic component according to the present invention irradiates light at a brightness that images only the package part that does not include the leads of the component. After performing image recognition and positioning with rough precision, light is irradiated with a brightness that creates an image of the entire part including the leads, and image recognition is performed to perform accurate positioning.

(e) Effects The above method for recognizing the position of an FP type electronic component allows the position of the component to be quickly and accurately recognized even if the component is held with rotational deviation or suction position deviation.

(F) Embodiment FIG. 1 is an explanatory diagram of the component positioning process in the position recognition method for FP type electronic components of the present invention, and FIG. 2 is a configuration diagram of the positioning means. Reference numeral 1 denotes an FP type IC, which is held by suction on a mounting head 2 rotatably attached to an XY table 3. 4 is a lighting device that illuminates the parts to be picked up by the mounting head 2; 1 control device fl! The brightness changes step by step according to the instructions in step 6.

Reference numeral 5 denotes an imaging means such as a television camera, which captures a shadow image of the component illuminated from behind by the illumination device 4, and performs image recognition and positioning by the control device 6. 7 is a conveyor that conveys a printed circuit board on which parts are mounted.

An example of an image taken by the imaging means 5 shown in FIG. 1 will be explained below.

The FP type ICI adsorbed on the mounting head 2 is positioned directly above the imaging means 5 by moving the XY table 3, and the irradiation light of the illumination device is adjusted to the first instruction value set in advance in the control device 6. Then, set the brightness so that only the part of the package that does not include the leads is imaged, and take the image. This is achieved by increasing the luminous intensity of the lighting device 4. Even if the FP type IC is sucked in a rotationally misaligned state as shown in Figure 1a, image recognition of the rectangular part of the package is performed.
The dimensions, center of gravity, and inclination are calculated by the control device 6 to perform rough positioning. Then, according to instructions from the control device 6, the mounting head 2
rotates to correct rotational deviation as shown in Figure 1.

Next, the irradiation light of the illumination device is set to a brightness that allows the entire component including the leads to be imaged using a second instruction value set in advance in the control device 6, and the FP IC is imaged. Now it's time to reduce the brightness of the lighting device. As shown in FIG. 1C, image recognition is performed for the entire part in the same manner as in the conventional method, and fine positioning is performed.

The same method can be applied even when the center of the suction nozzle is stt from the center position of the part, and after performing approximate position correction by moving the XY table 3 by the amount of deviation, fine positioning using the conventional method is performed. conduct.

(G) Effects of the Invention As described above, the method for recognizing the position of an FP type electronic component of the present invention enables highly accurate positioning in a relatively short time without being affected by the adsorption/holding state of the FP type electronic component. It becomes possible. Therefore, when mounting an FP type electronic component onto a printed circuit board with high precision, it is possible to reduce the mounting time.

[Brief explanation of drawings]

Fig. 1 is a process explanatory diagram of the position recognition method of the present invention, and Fig. 2 is a block diagram of the position recognition device. Figs. 3 and 4 are schematic diagrams illustrating conventional position recognition. Yes. 1...FP type IC, 2...Mounting head, 3...X
Y table, 4... illumination device, 5... imaging means, 1
62 control device, 7...conveyor, 8...sample straight line, 9...area reflected on the imaging means.

Claims (1)

[Claims] (1) When recognizing the position of a flat package type electronic component by image recognition using an imaging means such as a television camera, first image only the main body part of the flat package type electronic component, not including the leads of the component. After performing image recognition by irradiating light at a brightness that allows for rough positioning, we perform image recognition by irradiating light at a brightness that will image the entire part, including the leads, and use the lead as a reference. A method for recognizing the position of flat package electronic components, which is characterized by highly accurate positioning.